During this fiscal year, this project, originally begun when Dr. Bailey-Wilson was a Professor at Louisiana State University Medical Center, has been continued. Work accomplished in this fiscal year has included screening of cases and collection of family data collection and blood and tissue samples. The purpose of this study is to identify a gene or genes that contribute to lung cancer susceptibility. The specific aims are to 1) collect family history and environmental risk factor data about lung cancer from lung cancer patients and their families and to also collect blood and tissue samples from a subset of the families that appear informative for linkage analysis; 2) genotype the biological samples for a genome wide set of marker loci; 3) perform a genome-wide linkage analysis to attempt to localize a lung cancer susceptibility locus (loci). In this fiscal year, family history and biologic samples have been collected from both new and previously studied families. Data collection on six new families has been completed in this fiscal year and many other new families are being studied. Data collection is ongoing and expected to continue for several more years. Dr. Bailey-Wilson has been instrumental in founding the Genetic Epidemiology of Lung Cancer Consortium (GELCC) for the purpose of obtaining additional family data from a large group of collaborative investigators. Genotyping, including fine mapping, in candidate regions has been completed on five of the most informative GELCC families, including two of Dr. Bailey-Wilson's families. Dr. Bailey-Wilson and her collaborators have analyzed these families and have obtained some evidence of linkage in one of these regions. However, the extremely small sample size requires that conclusions be postponed until more data are available. Additional families are currently being genotyped for approximately 400 markers at the Center for Inherited Disease Research (CIDR). Approximately one-fifth of this set of families are from the Louisiana data collection effort. As head of the GELCC Analysis committee, Dr. Bailey-Wilson will be in charge of the analyses of these data. Genotype data from the genome wide screen of the larger number of families will be analyzed in the next fiscal year. In addition, we are about to send more families to CIDR for genome wide screen genotyping.